A vibration damping device for canceling out a vibration caused by a vibration generating source such as an engine of a vehicle or the like and a canceling vibration generated through vibration applying means at a position to be damped is conventionally known. Patent Document 1 discloses, as such a conventional vibration damping device, a vibration damping device that calculates a pseudo vibration corresponding to a vibration to be damped using an adaptive control algorithm, generates a canceling signal on the basis of the calculated pseudo vibration, makes a canceling vibration generated at a position to be damped through vibration applying means such as an actuator or the like on the basis of the canceling signal, detects a vibration remaining as a cancellation error between the generated canceling vibration and the vibration to be damped by an acceleration sensor, adapts the adaptive control algorithm by learning so as to reduce the detected vibration remaining as the cancellation error, and converges the pseudo vibration to a true value.
The vibration damping device illustrated in Patent Document 1 determines the frequency of the pseudo vibration assuming that a frequency recognized on the basis of an engine crankshaft rotation pulse signal coincides with the frequency of the vibration to be damped. Other vibration damping devices generally recognize the frequency of a vibration to be damped and determine the frequency of a pseudo vibration on the basis of a signal related to a vibration generating source.
In addition, a vibration damping device for canceling out a vibration caused by a vibration generating source such as an engine of a vehicle or the like and a canceling vibration generated through vibration applying means at a position to be damped is conventionally known. Patent Document 1 discloses, as such a conventional vibration damping device, a vibration damping device including: control means for receiving a frequency corresponding to a vibration caused by a vibration generating source and generating a canceling signal for canceling the vibration transmitted from the vibration generating source to a position to be damped; vibration applying means for generating a canceling vibration at the position to be damped, the vibration applying means being actuated by being supplied with a canceling signal generated by the control means; and vibration detecting means for detecting a vibration remaining as a cancellation error between the vibration caused by the vibration generating source and the canceling vibration at the position to be damped; wherein the control means corrects the canceling signal so as to reduce the vibration remaining as the cancellation error on the basis of the vibration detected by the vibration detecting means.
In addition, a vibration damping device for canceling out a vibration caused by a vibration generating source such as an engine of a vehicle or the like and a canceling vibration generated through vibration applying means at a position to be damped is conventionally known. Patent Document 1 and Patent Document 2 disclose, as such a conventional vibration damping device, a vibration damping device that calculates a pseudo vibration corresponding to a vibration to be damped using an adaptive filter, makes a canceling vibration generated at a position to be damped through vibration applying means such as an actuator or the like on the basis of the calculated pseudo vibration, detects a vibration remaining as a cancellation error between the generated canceling vibration and the vibration to be damped by an acceleration sensor, repeats the calculation of the adaptive filter so as to reduce the detected vibration remaining as the cancellation error, and converges the pseudo vibration and the adaptive filter to a true value by accumulation of calculations.
The vibration damping device performing such adaptive control generally accumulates the calculations of the adaptive filter using a convergence coefficient indicating a degree by which the adaptive filter is brought closer to the true value per calculation. The convergence coefficient determines a speed at which the adaptive filter converges to the true value. As illustrated in Patent Document 2, a fixed convergence coefficient is generally used as the convergence coefficient.